Multiple choice general knowledge science & technology The heat energy produced when the human body metabolises 1 gram of fat is 30 KJ 1 KJ 39 KJ 29 KJ Reveal answer Fill a bubble to check yourself C Correct answer Explanation When 1 gram of fat is metabolized, it produces approximately 37-39 kJ of heat energy. This is higher than carbohydrates or proteins, which is why fats are energy-dense nutrients.